Among possible attacks used by fraudsters to extract confidential data from a memory of an integrated circuit, for example a protected memory of a smart card, mention may be made of differential fault analysis (DFA) attacks, which attempt to disrupt the operation and/or the content of the memory, or even to modify the logic of the circuit, for example by means of a radiation (laser, infrared, X-ray, etc.) beam.
Such a radiation beam may be emitted through the front side of the chip. To protect against such an attack, the front side of the chip is generally equipped with a particularly dense metal grid forming a protective screen and intended to absorb most of the energy of the laser beam. Moreover, this grid is electrically connected to certain components of the integrated circuit, thereby allowing the integrity thereof to be regularly monitored, in case the attacker tries to remove at least part of this grid.
Such a radiation beam may also be emitted through the back side of the chip. It is therefore particularly desired to protect the electronic circuit from a back-side laser attack.